Electric-furnace signal



Patented Jan. 15, 1924.

WAITER w. Milton, or OAKLAND, cALVIFoBNm.

ELECTRIC-FURNACE SIGN L.

Application led July 3,

To ill `whom #may concern.'

,Be it knwn that I; ama W- MIRQN, a citiaen ofthe United` States, residing at OaklandfinA the county ofQAlanieda and State of I@aliforma, haveffinvented certain new and `usef Iliiprovements in Electric- Furnace Signals,,of'wl'iichxthe following is a speciic'ation.r

The object of, my invention is to provide an electrically operated, automatic signal system. The purposepartcularly of the device is its use irl-'an electric 'metal melting furnace as a telltale Ysiignaliipon, the Contact of the electrodeiwith a solid-,bodyof metal 1 in the bottom of the furnace, or contact with the bottoimofthe furnace..

The inventionis so constructed that I,it may: be adapted for use in conjunction with a furnace having any number of electrodes which might be operating in a furnace and l. do not conne myself to any particular number of electrodes to which my system might be adapted.

l utilize an ordinary electric bell which gives warning of the contact between the solid metal and electrode, an annunciator drop indicates the particular electrode in contact with the metal being melted or the bottom of the furnace. The invention is extremely simple and the following specifications will enable anyone to construct this invention who is familiar with the art to which it appertains.

Referring to the drawings in which like numerals designate like parts in all the views; Fig. 1 is a front view of the device. Fig. 2 is a side view, Fig. 3 a typical wiring diagram of the device as applied to a metal melting furnace utilizingfour electrodes for the production of heat, and Fig. 4 shows another position in which the invention can be applied to an electro metal melting furnace.

Referringr to the several views, the contactor, l is shown clearing part of the frame 16 of the furnace. The contactor 1 is fastened in a secure manner to the insulated bracket block 2, by the bolts and nuts 20. The insulated bracket block 2 is held in a rigid position by the U clamp bolt and nuts 3, the bolt embracing the guide pin 4. Electrical connection is made to contactor 1 by the insulated wire 5. Insulated wire connections 6, 7, and 8, are connected to other elec- 1919. serial ne, 305,304.r

trodesi'not shown.Y i The annunciator drops 9 indicatehthe Vparticular electrode which has come in contactV with thesolid metal or bottom of the fuiiace'21- The signal Vbell i 1,0', isfof the ordinary cbnstrhction, and -is conneeted'in such a Ii'iann'er that the ciosing of the circuit Vcauses it Ato ring. Incandescent lamps V11,` areV connected in multiple seriesthe purpose of which is to reduce the line volta ',e. has beeii found in practice that having 110 volts alternating current vwith three V54 watt` lamps, 11 in series on the ricain annunciatorlfeed wires 23, there is obtainedrOv'olts drop on'the line and the altriiatingcurrent flowing through the systemV operates the, six volt direct ourrent Ibell 1() and' the annunciator 9 series. "The yelt-ctrical isthrwn out of scrvicewi'th the main fed wires 23, by the single pole switch 12. The electrode carrying arm 13 is connected with a shaft not shown in the drawings and which moves the electrode carrying arm 13, thereby causing the electrode carrying arm 13 to raise and lower the electrode 17. The electrode carrying arm 13, travels between the two channel irons of the frame 16, and is held in position by the guide wheels 14 turning on the guide wheel pins 24; and the guide pins 4, and 15, which are in contact with the frame 1. The carbon electrode 17, or any other suitable material, is fastened in a secure and rigid manner to one end of the electrode carrying arm 13. The furnace 18 is a type of electric furnace used for the melting of metals. The U bolt 3 and nuts 19 hold the bracket insulated block 2 in a rigid manner to guide pin 4. The wiring system is grounded on the frame of the furnace at 22. The metal in the bottom of the furnace is shown by 21.

Having thus descrfbed the component parts of my invention, I will describe the operation of the invention, the main object of the device is to give warning at the time contact takes place between the electrode 17 and the metal 21 or between the electrode 17 and the bottom of the furnace. In practice it is found that if the electrode comes in contact with a solid hard substance, and the electrode carrying arm 13 continues its downward movement there is no alternative but that the electrode 17 must break thereby being destroyed causing considerable ex- (lil pense and delay, which I claim that my invention is adapted to overcome inthe folloivin manner.

If t e electrode 17 on being fed Vdown into the furnace, should make contact with the solid metal 21, or the bottom of the furnace 1S, it would cause the electrode 17 and the electrode carrying arm 13 to tilt (due to poor connections in the mechanism) and more outward. As the contacter l1 is fastened to the electrode carrying arm 13, and the pin 4, b means of the U bolts and nuts 19 and insu ated from the bracket block 21, it would, due to the small clearance between it and the frame 16 make a contact with the frame 16, thus closing the circuit and causing the bell 10 to ring and the annunciator 9, to drop and thereby give a positive signal of the particular electrode in contact Wit-h the solid body of the metal in the furnace. It has however been found in practice that no particular harm can result Where the electrode comes in contact with metal when in a molten state and does not touch the bottom of the furnace.

It is found in practice that my invention does all that I claim it Will do, and the construction is extremely simple, inexpensive, and practical. It is readily adapted to any particular furnace in use; as I do not contine myself to any particular make of furnace or kind.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

1. In an electric furnace, the combination withV a movable electrode; of a supporting arm carrying said electrode, a support on which the arm is slidable and also free to tilt upon contact of the electrode with an obstruction` an electro-responsive signal device, and a switch controlling said device and operated by the tilting movement of the aforesaid arm.

2. In an electric furnace, the combination with a movable electrode; of a supporting arm carrying said electrode, a support on which the arm is slidable and also free to tilt upon contact of the electrode with an obstruction, an electro-responsive signal device, an energizing circuit for said device grounded on the aforesaid support, and a switch blade carried by the aforesaid arm, said blade making contact with the support when said arm tilts.

In testimony whereof I atXed my signature.

WALTER W. MIRON. 

